Add tests for base64.

Makefile

@@ -158,6 +158,7 @@ endif
 
 # Programs with usable tests
 TEST_PROGS  := \
+  base64 \
   basename \
   cat \
   cp \

test/base64.rs

@@ -0,0 +1,95 @@
+use std::io::{Read, Write};
+use std::process::{Command, Stdio};
+use std::str::from_utf8;
+
+static PROGNAME: &'static str = "./base64";
+
+struct CmdResult {
+    success: bool,
+    stdout: String,
+    stderr: String,
+}
+
+fn run_piped_stdin(cmd: &mut Command, input: &[u8])-> CmdResult {
+    let mut command = cmd
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn()
+        .unwrap();
+
+    command.stdin
+        .take()
+        .unwrap_or_else(|| panic!("Could not take child process stdin"))
+        .write_all(input)
+        .unwrap_or_else(|e| panic!("{}", e));
+
+    let prog = command.wait_with_output().unwrap();
+    CmdResult {
+        success: prog.status.success(),
+        stdout: from_utf8(&prog.stdout).unwrap().to_string(),
+        stderr: from_utf8(&prog.stderr).unwrap().to_string(),
+    }
+}
+
+macro_rules! assert_empty_stderr(
+    ($cond:expr) => (
+        if $cond.stderr.len() > 0 {
+            panic!(format!("stderr: {}", $cond.stderr))
+        }
+    );
+);
+
+#[test]
+fn test_encode() {
+    let input = "hello, world!";
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd, input.as_bytes());
+
+    assert_empty_stderr!(result);
+    assert!(result.success);
+    assert_eq!(result.stdout, "aGVsbG8sIHdvcmxkIQ==\n");
+}
+
+#[test]
+fn test_decode() {
+    let input = "aGVsbG8sIHdvcmxkIQ==";
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd.arg("-d"), input.as_bytes());
+
+    assert_empty_stderr!(result);
+    assert!(result.success);
+    assert_eq!(result.stdout, "hello, world!");
+}
+
+#[test]
+fn test_garbage() {
+    let input = "aGVsbG8sIHdvcmxkIQ==\0";
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd.arg("-d"), input.as_bytes());
+
+    assert!(!result.success);
+    assert_eq!(result.stderr, "base64: error: invalid character (Invalid character '0' at position 20)\n");
+}
+
+#[test]
+fn test_ignore_garbage() {
+    let input = "aGVsbG8sIHdvcmxkIQ==\0";
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd.arg("-d").arg("-i"), input.as_bytes());
+
+    assert_empty_stderr!(result);
+    assert!(result.success);
+    assert_eq!(result.stdout, "hello, world!");
+}
+
+#[test]
+fn test_wrap() {
+    let input = "The quick brown fox jumps over the lazy dog.";
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd.arg("-w").arg("20"), input.as_bytes());
+
+    assert_empty_stderr!(result);
+    assert!(result.success);
+    assert_eq!(result.stdout, "VGhlIHF1aWNrIGJyb3du\nIGZveCBqdW1wcyBvdmVy\nIHRoZSBsYXp5IGRvZy4=\n");
+}